Patent GB-191010125-A (GB)
Title: An Improved System of Railway Signalling, with Responsive Connection Back to the Signal-box, and Apparatus therefor.
Inventor: CHAPMAN FREDERICK CHARLES
IPC: B61L3/08
Filed: 1910-04-26
Granted: 1911-04-20
Abstract: 10,125. Chapman, F. C. April 26. Track apparatus actuating signals on trains; miniature signals and indicators.-A fixed electric track conductor mounted between the rails adjacent to each semaphore closes a circuit, which passes through switches on the ordinary semaphore and through a collecting-brush to an indicator on the engine, and the direction of the current determines whether a ' safety ' or ' danger ' indication is given on the engine corresponding to the position of the semaphore. The track conductor is also connected to a testing magnet in the cabin to test its working order. A mechanical track contact comprising an inclined plane pivoted at one end is also raised by connections with the semaphore when ' danger ' is indicated, and a pivoted arm on the engine is thus rocked to give a whistle signal and apply the vacuum or steam brakes. An electric switch at the mechanical track contact closes circuits, which operate a cabin indicator showing the position of the track contact. A single mechanical track contact may be controlled by two distant semaphores. At a junction of two roads where there are two home semaphores, the circuits of the single track conductor pass through the switches on one or other semaphore according to the position of a rod fixed similarly to the points stretcher bar and carrying two sets of electric contacts. Fig. 2<A> shows the connexions of a revolving switch B<2> on the semaphore B<4> having two sets of brushes B<5> with a battery B<1> and a track contact B<6>, so that the polarity of the connection to the contact B<6> will be reversed when the semaphore B<4> is lowered. Brushes C<2>, C', Fig. 8, for the home and distant contacts B<6>, A<6>, respectively, are provided on the engine, and leads from these brushes connect to separate distant and home miniature semaphore indicators in the cab with a common return lead to the ordinary wheels and the track rails R. A handle G operates a cut-out switch in this circuit when the apparatus is to be thrown out of action, and a reversing switch is used to reverse the connection of the brushes to the ' home ' and ' distant ' engine indicators when the engine runs tender foremost. Springs C<12> press the brushes on to the contact rails, and the brushes may be raised out of action by the engine driver operating the handle G, Fig. 7, which through a link G<8>, a lever G<9>, and a link G" rocks a shaft M', which by means of a lever K<2> and a collar C<8> raises the brush. The mechanical track contact actuates one or other of two arms F, Fig. 6, and by means of chains L and chain wheels on the shafts F', M' opens two valves M to a whistle and the brake pipe respectively. When the handle G, Fig. 7, is operated to raise the brushes, two valves G', G<2> connecting the valves M to the whistle and brake pipe are shut, and the arms F are simultaneously raised out of action by the handle G through the link G<8>, lever G<9>, link G<11>, arm K<1>, rock shaft M', the chain-wheels and chain L, and shaft F', provided that a treadle N is also depressed by the engine driver to move a clutch O, Fig. 6, and gear the chainwheel L' with the shaft M'. The mechanical track contact comprises an inclined bar D, Fig. 4, mounted on a pivot D<7> and operated by a connexion D<3> from the semaphore. A rotary electric switch of the kind described in connexion with the semaphores is mounted on the shaft D' to close circuits which actuate cabin indicators to show the position of the track contact D. When the contact D is controlled from two semaphores, two levers D<4>, Fig. 4B, connected each with a semaphore are mounted loosely on the shaft D', and engage by a projection on the boss of each with a corresponding projection on the boss of a lever d<5>, which raises the contact D. The Provisional Specification also states that cams are fixed in the track immediately preceding the electric track conductors, and an arm on the engine is vibrated by each cam to warn the driver by actuating an electric or other bell.